Pumping system



Nov. 10, 1931. BRADFORD 1,830,923

PUMPING SYSTEM Original Filed May 14, 1926 Patented Nov. 10, 1931 mm srAEs PATENT OFFICE FREDERICK E. BBADI'ORD, OI CHICAGO, ILLINOIS, ASSIGNOR'10 AUTOMATIC P311153 comm, OF CHICAGO, ILLINOIS, A OORPOBAT'ION OFILLIN'OIS,

' ammo stem Application fled Kay 1;, 1m, Serial No. 109,087. RenewedNovember 19, 1887.

in the present invention are disclosed in the Patents 1,314,875 ofeptember 2, 1919 1,377,256 of Mav 10, 1921, and 1,419,273 of June 13,1922, all of which were granted to H. E. La Bour of Chicago, Illinois.

Such systems, however, have certain defacts which are overcome by thepresent invention. Obviously, if there is not enough liquid in thepriming tank, a system of this kind will not start to operate. Also ifduring pumping a, suflicient uantit of the liquid becomes replaced by te co ection of air or'any other gases in the priming tank, the systemwill also become air bound. That is to say, enough gas will collect inthe priming tank to lower the liquid level below the pump intake to stoits operation. This is due to the fact t at centrifugal pumps cannotsuck air.

It is so nearly impossible-to keepair and other gases from entering thepriming tank that it is impractical to attempt to do this.

Gases in solution may become disentrained when coming into the region ofreduced pressure in the tank, or they may also be drawn up from thesource with the liquid as bubbles. The quantity of air or gas 1n theprim-' air into the surrounding. atmosphere while the liquid is fed froma point somewhat below the top of the separating tank to the tionprovides a primary separating distributing system. This inventioncontemplates a novel and simplified vent for such separating tanks.

Another part of the present invention pro- I vides' for a speciallylarranged inlet to the primin tank from t mizes e air space between thelift pipe inlet and the top of the riming tank.

Still another form oi tank having an automatically controlled -pass pipebetween it and the priming tank, for removing'air from the primingtankduring pumping and which also performs the function of the vacuum breakin the Patent No. 1,417,273 above'cited.

In order that the invention ma be under- 1 stood by. those skilled inthe rtment art,*it will hereinafter be disclose as embodied in aspecific form which will be described in detail. Many other forms may bederived from the following disclosure and other uses e lift pipe whichmini-.

the present inven-' may be. found to which this inventionmay lenditself.

In the accompanying sheet of drawing matter;

- Figure 1 is an elevation of the'meohanism m 'w 1ch the presentinvention is embodied,

the:1 most important parts being in section; an v Figure 2 is a similarview of a modified arran ment of a similar mechanism.

In igure 1, 5 indicates a centrifugalor valvelessgmmp having a powershaft 6 ada ted to be riven b any suitable means which ma be controlleautomatically or manually an which form no part of the resent invention.The pump 5 has an inta e 7 and an outlet pipe 8. The intake connectswith a priming tank 9 and the outlet communicates with a store e andseparating tank 10. A suction or li assembly. It will be apparent fromthe drawing that a minimum of air space exists pipe 11 is brought intothe A priming tank 9 as close to the top as possible,

and also to be at as low a level as possible 9 from the main separatingtank 10. The vent between the top of the tank and the inlet pipe. Theend of the tank is then inserted and welded into place, after which thepipe 11 is welded at 28. The pipe 11 is then connected with a well, asat 13, and is provided with a satisfactory screen 14 for keeping solidmaterial out of the system.

.The storage tank is provided with an outlet 15 which may lead to thedistributing system. Any desired type of distributing system ma be usedwith this suppl system. The out et '15 is located somewhat low the topof the tank in order that air or other gases may collect at the top toescape through a vent 16. This vent comprises a pipe which may lead backto the well or to any desired point and is of a diameter small enough toofl'er suflicient resistance to the flow of the liquid therethrough,which results when the air becomes expelled from the tank 10, so thatthis flow is negligible.

The vacuum break before mentioned comprises the small pipe 17 betweenthe inlet to the separating tank and the priming tank. This pipe is of adiameter sufiiciently small to reduce the leakage therethrough, when thepump is in action, to a negligible amount.

The novel means for expelling air from the priming tank during operationcomprises a pipe 18 opening at or near the top of the tank 9 andconnecting with an air ejector n the pump intake 7 at its other end. Atthis point there is placed a venturi 19 having openings 20 through itsneck, and leaving a space 21 between its neck and the inside of the pipe7. This novel ejector clears the priming tank of gas during the time thepump is bein operated.

In the modification shown at Figure 2, the pump, lift pipe, andseparating tank arrangement is substantially the same as that shown inFigure 1 and the identical parts bear like reference numerals. Betweenthe pump and the storage tank, however, there is inserted a' primaryseparation tank 21 connectedwith the priming tank by a p1pe 22 which iscontrolled by a valve 23 operable only by the pressure in the tank 10.T1118 pressure is transmitted to the valve mechanism by the conductor 25and closes the p1pe 22 when the pressure reaches a predetermined amount.Inasmuch as pressure controlled valves are old in the art, and that anyconvenient type which will serve this purpose maybe used, the detailsthereof need not be described.

A vent valve 24, adapted to be closed when the liquid level in the tank10 is above a predetermined point, permits the gas to escape 24 beingclosedby the rising of the liquid in the tank 10 causes a pressure tobuild up therein which actuates the valve 23, which in turn closes theby-pass 22.

Referring now to Figure 1, the operationrsaopaa of this device comprisesseveral stages. Assuming that the amp is at rest and that the system isprimed to the level L-L, the lift ppe will contain only air. If then,the pump started, it will tend to draw out the liquid in tank 9-. Thiswillcreate sufiicient suction to raise the liquid in the lift pipe untilit spills into the priming tank.

It is obvious that, as the liquid begins to spill into the tank, therewill be a large percentage of ratified air in the tank 9. This quantityof gas will tend to increase until, as before explained, the pump intakeis no longer flooded and the system becomes airbound. However as soon asthere is a fiow created in the pipe 7, the venturi located therein willcommence to draw the air from the upper part of the tank and eject itthrough the pump in a manner which will be well understood by thosefamiliar with the pertinent art. As the pumping action contlnues, thepercentage of air in the tank will become less and less until liquidwill be drawn through the venturi through the pipe 18. This system iscapable of expelling any normal amount of air or other gases which maybe dissolved, suspended, or otherwise entrained in the fluid.

As soon as the liquid starts to rise in the tank 10, the air thereinwill be expelled through the vent pipe 16. It will be noticed that thepipe 15 enters the tank at a level substantially below the top of thetank in order to permit air or other gases to collect at the top. Afterall the gas has been expelled from this tank, the liquid will flowthrough the pipe 16, which may be led back to the source or to any suitable sewer or drain as desired. This pipe is of such a small diameterand is preferably made long enough to offer enough resistance to theflow, so that the leakage therethrough when the system is deaerated willbe negligible.

Upon the stopping of the pump, the column of liquid in the lift pipe andthe pressure of the liquid in' the storage tank will tend to siphon outthe system until the air will bubble through the vacuum break 17 whichis connected between the priming tank and the pump outlet at a levelapproximately the top of the priming tank. As soon as the system hasbeen emptied to -this level, any air whichwill have been drawn inthrough the vent will be drawn through this pipe and bubble through theliquid in the tank 9 to break the suction, as explained in Patent No.1,410,27 2. This obviates the draining of the pump and a part of thepump outlet. The resistance of this pipe can also be made great enoughto render leakage through it negligible when the system is in operation.

Referring now to Figure 2, the modification here disclosed operates in adifferent manner. Assuming a sufliciency of liquid in the tank 9, theinitial operation is the same dition into t e prima as that ,of FigureThe pump then start to pum liquid and air in a mixed conseparatin tank21'.

The entrained air will freed an naturally .pass on to the tank 10, butsome substantially air-free liquid will be pumped back to the tank 9to'entrain more air, which will also be separated. If enough liquidremains in the system to fill the tank 21' so that it will spill throughthe ipe 22, which is of higher resistance than t e main line, the system7 willbe self priming. As the liquid circulates Y pipe 22, and back tothe the tank 10 drops from the priming tank through the pump and"priming tank, entraining air each time, w ich is also separated eachtime and forced into the tank 10, the effect produced is equivalent tothe pump pumping out the air from the tank 9 into the tank 10.

As the air enters the tank 10, it escapes .through the vent 24. As longas the valve 24 is open, it is obvious that substantially no pressurewill be developed at the top of the tank 10 to close the valve 23. Thevalve 24 is designed to be operated by the liquid level in the tank andbe substantially independent of the pressure in the tank. When the tankbecomes substantially full of liquid, the valve 24 closes causing thepressure to build up, thus closing the valve 23 and permitting thesystem to function to deliver water. It has been found in actualpractice that any normal amount of air which may collect in the tank 9will be entrained in the flow and collect at the top of tank 10. Whenduring normal pum ing the liquid level in elow a predetermined point,because of accumulation .of air or other gas the valve 24 blows off andlets substantially all the air out of the tank. The rising of the liquidin the tank attendant upon exulsion of the air again closes the valve24. %y this arrangement the system becomes antom'atically selfdeaerating. As long as some air exists in the priming tank a portion ofit will be entrained in the liquid flow and collect at the top of thestorage and separating tank. This gas will collect here to cause thevalve 24 to open before the system becomes air bound.

When the pump is stopped the liquid col-' umn in the lift pipe 11 andthe pressure of the liquid in the storage tank start to drain out thesystem, as is the case in the mechanism shown in Figure 1. This may tendto create a partial vacuum at the top of the tank 10, vbut the liquidlevel is thereby lowered and, the valve 24 opens and breaks the'vacuum.When the liquid is drawn to the level of the pipe 22, the valve 23,having been opened by the decrease in pressure in tank 10, permits thepipe to function in the same manner as the vacuum break 17 in Figure 1,and the system is ready to be operated again.

Air or other gases in the priming tank are detrimental. If the(presslilre flefquired to int e pipeis lift the column of liqui tenpounds, or two thirds atmospheric pressure the pressure in the primingtank as the liquid starts to spill in must-be one third atmosphericpressure or five pounds. Inasmuch as the volume of a gas variesinversely as the pressure applied, any gas which may exist in thepriming tank at the beginning of the priming operation will occup threetimes its normal volume as the liquid starts to spill into the primingtank from the lift pipe. It follows then, that, in addition to theliquid necessary to raise the liquid up the lift pipe, an extra quantityat least three times as great as the volume of air initially in thepriming tank will be necessary. This, of course, requires a larger tankthan if all the air could be excluded therefrom.

Thus it is quite apparent that the percentage of the gas which mustremain in the priming tank is an important factor in determining thesize of the tank. Also, it isan equally important factor in determininghow much pumping the pump must do before it can begin to supply thedispensing system with liquid. Therefore, this gas percentage is a largefactor in determining the over-all efiiciency of the pump as well as thesize of the tank and hence the cost of the apparatus. The higher thelift the greater the effect a given percentage of air in the primingtank will have in determining the size of the tank. Thus, thedome-shaped top for the priming tank, which is a part of the presentinvention, serves a novel and useful purpose.

It is apparent that various modifications and arrangements may be madein the disclosed structure without deviating from the scope of thepresent invention. It is also apparent that the position of the gas andliquid may be reversed and the flow of the gas be used to eject anyliquid which might collect in a storage tank of some kind. It is,therefore, not intended that the scope of this invention be limited tothe above disclosure, but that it shall be limited only by the scope andspirit of the appended claims.

I claim a 1. In combination, a centrifugal pump, a container having anupper opening connecting with a liquid source and a lower openingconnecting with said pump by a pipe, a Venturi nozzle in said pipeconstructed to leave a space between its neck and said pipe, and havingopenings in said neck communicating with said space, and afluidconductor between said space and the upper portion of thecontainer. I

2. In combination in a pumping sys em comprising a container for liquidand a storage tank, a centrifugal pump, a pipe connecting the intake ofthe pump to the container, said pump discharging into the tank, aventuri fitting snugly within the pipe and having are its restrictedportion aced away from the surrounding wall of t e pipe, the venturihavin an opening communicating .with the space Ixatween the restrictedportion thereof and the pipe, and a conduit establishing communicationbetween the container above the level of the li uid column and saidspace.

i 3. In combination in a umping sys'te a priming tank, a source 0suppliy of liqul communicating with the tank a jacent the top thereof, astorage tank above the primingtank, a centrifu connecting the inta e oft e pum to t e lower portion of the priming ta a discharge pipeconnecting the discharge of the pump to the storage tank remote from thetop thereof, a venturi fitting snugly within the intake pipe and havingits neck portion spaced from the surrounding wall of the pipe andprovided with an opening extending therethrough, a conduit connectingthe space between the neck portion of the venturi' and the pipeto theupper portion of the priming tank, and a conduit of restricted areaconnecting the discharge pipe to the upper portion of the priming tank.

4. In combination in a tank structure, a hollow body provided with topand bottom heads, an intermediate head within the body and separating itinto an upper tank and a lower tank, said intermediate head being ofsubstantially concavo-convex cross-section with its under surfaceconcaved, and a pipe extending through the wall of the upper tank abovethe intermediate head and opening throu h said intermediate head intothe lower tan said pipe being secured to the intermedia e head and tothe wall of the upper tank, the inner end of said pipe beingsubstslzlrligtially flush with the roof of the lower ta a In witnesswhereof, I hereunto subscribe my name this 12th day of May, 1926.

FREDERICK H. BRADFORD.

lpum an intake pi e

